But how will you manage your internal LAN from "the cloud" if your configuration isn't created, stored and managed from "the cloud"? Surely, you aren't some heathen who would rather not create the extra attack surface of having all that exposed to the internet? No, this is The Way. Cloudify ALL THE THINGS! No local configs. Trust "the cloud" to always be there. There has never been any example of service providers turning off cloud services and leaving users with expensive door stops. Nope, never. There is no Nest of products for which this had happened.
Sarcasm aside, never buy hardware which can't be used without a proprietary cloud service. If you can't turn those requirements off, then you don't really own the device. You're just renting it with a high, up-front activation fee and the requirement to handle disposal. Even worse, you get to go through all those costs again when the company decides you need to buy a new version.